Methods for producing silicon nitride films by vapor-phase growth

ABSTRACT

Methods for the production of silicon nitride films by vapor-phase growth. A hydrazine gas and at least one precursor gas are fed into a reaction chamber containing a substrate. The precursor gas is either a trisilylamine gas or a silylhydrazine gas. A silicone nitride film is formed through the reaction of the hydrazine gas and the precursor gas.

This invention relates to methods for producing silicon nitride filmsand more particularly relates to methods for producing silicon nitridefilms by vapor-phase growth, such as chemical vapor deposition (CVD).

Silicon nitride films have excellent barrier properties and an excellentoxidation resistance and as a consequence are used in the fabrication ofmicroelectronic devices, for example, as an etch-stop layer, barrierlayer, or gate insulation layer, and in oxide/nitride stacks.

Plasma-enhanced CVD (PECVD) and low-pressure CVD (LPCVD) are the methodsprimarily used at the present time to form silicon nitride films.

PECVD is typically carried out by introducing a silicon source(typically silane) and a nitrogen source (typically ammonia, but morerecently nitrogen) between a pair of parallel plate electrodes andapplying high-frequency energy across the electrodes at low temperatures(about 300° C.) and low pressures (0.001 torr to 5 torr) in order toinduce the generation of a plasma from the silicon source and nitrogensource. The active silicon species and active nitrogen species in theresulting plasma react with each other to produce a silicon nitridefilm. The silicon nitride films formed in this manner by PECVD typicallydo not have a stoichiometric composition and are also hydrogen rich andaccordingly exhibit a low film density, a poor step coverage, a fastetching rate, and a poor thermal stability.

LPCVD uses low pressures (0.1 to 2 torr) and high temperatures (800° C.to 900° C.) and produces silicon nitride films with a quality superiorto that of the silicon nitride films produced by PECVD. At the presenttime silicon nitride is typically produced by LPCVD by the reaction ofdichlorosilane and gaseous ammonia. However, ammonium chloride isproduced as a by-product in the reaction of dichlorosilane and gaseousammonia in this LPCVD procedure: this ammonium chloride accumulates inand clogs the reactor exhaust lines and also deposits on the wafer.Moreover, existing LPCVD technology suffers from a slow rate of siliconnitride film growth and has a high thermal budget. In order to reducethis thermal budget for the production of silicon nitride films, amethod has very recently been developed that produces silicon nitridefilms by reacting ammonia with hexachlorodisilane used as a siliconnitride precursor. This method, however, suffers from a pronouncedexacerbation of the problems cited above due to the large amounts ofchlorine present in hexachlorodisilane. Silicon-containing particles arealso produced by this method, which results in a substantial reductionin the life of the exhaust lines. Finally, this method can providehigh-quality silicon nitride films (good step coverage ratio, lowchlorine content) at excellent growth rates at a reaction temperatureof, for example, 600° C., but these characteristics suffer from apronounced deterioration when a reaction temperature ≦550° C. is used.

The use of carbon-containing volatile silazanes, azidosilazanes, andaminosilanes as silicon nitride precursors has been proposed in order tosolve the problems cited above (refer, for example, to non-patentreferences 1 and 2). However, these silicon nitride precursors, whetherused by themselves or in combination with ammonia, result in theincorporation of SiC and/or large amounts of carbon in the siliconnitride film product.

(Non-patent reference 1)

Grow et al., Mater. Lett. 23, 187, 1995

(Non-patent reference 2)

Levy et al., J. Mater. Res., 11, 1483, 1996

PROBLEMS TO BE SOLVED BY THE INVENTION

The problem addressed by this invention, therefore, is to provide avapor-phase growth method for producing silicon nitride films that canproduce silicon nitride films with improved film characteristics andthat can do so even at relatively low temperatures, without theaccompanying generation of ammonium chloride, and without significantadmixture of carbonaceous contaminants into the film product.

MEANS SOLVING THE PROBLEMS

According to a first aspect of this invention, there is provided amethod for producing silicon nitride films by vapor-phase growth, saidmethod being characterized by

-   -   feeding a hydrazine gas and at least 1 precursor gas selected        from the group consisting of trisilylamine gas and a        silylhydrazine gas into a reaction chamber that holds at least 1        substrate and    -   forming a silicon nitride film on said at least 1 substrate by        the reaction of the two gases.

According to a second aspect of this invention, there is provided amethod for producing silicon nitride films by vapor-phase growth, saidmethod being characterized by

-   -   feeding a silylhydrazine gas into a reaction chamber that holds        at least 1 substrate and    -   forming a silicon nitride film on said at least 1 substrate by        the decomposition of said silylhydrazine gas.

This invention is explained more specifically hereinbelow.

This invention, which relates to methods for forming silicon nitridefilms on substrates by a vapor-phase growth procedure such as CVD,employs trisilylamine ((H₃Si)₃N) and/or a silylhydrazine as siliconnitride precursors. These precursors produce a silicon nitride film by avapor-phase reaction with a hydrazine. Among these precursors, thesilylhydrazine can form a silicon nitride film by itself by thermaldecomposition.

The silylhydrazine used by this invention encompasses silylhydrazine asdefined by formula (I)H₃Si(R^(a))N—N(R^(b))R^(c)  (I)wherein R^(a), R^(b), and R^(c) are each independently selected fromsilyl, the hydrogen atom, methyl, ethyl, and phenyl.

The hydrazine that is reacted with the aforementioned precursorsencompasses hydrazines defined by formula (II)H(R¹)N—N(R²)R³  (II)wherein R¹, R², and R³ are each independently selected from the hydrogenatom, methyl, ethyl, and phenyl.

The method for producing silicon nitride film by reacting a hydrazinewith the aforementioned precursors (CVD procedure) will be describedfirst. In this case, a precursor gas, a hydrazine gas, and optionally aninert dilution gas are fed into a reaction chamber that holds at leastone substrate (particularly a semiconductor substrate such as a siliconsubstrate) and a silicon nitride film is formed on the substrate(s) byreaction between the precursor gas and hydrazine gas.

The interior of the reaction chamber can be maintained at a pressurefrom 0.1 torr to 1,000 torr during the reaction between the precursorgas and hydrazine gas, while maintenance of a pressure of 0.1 torr to 10torr within the reaction chamber is preferred.

The reaction between the precursor gas and hydrazine gas can generallybe carried out at temperatures (CVD reaction temperature) no greaterthan 1,000° C. However, almost no production of silicon nitride occursat temperatures below 300° C. Accordingly, the reaction betweenprecursor gas and hydrazine gas can generally be carried out at 300° C.to 1,000° C. This precursor and the hydrazine can produce siliconnitride at sufficiently high growth rates (film formation rate) even atlow temperatures of 400° C. to 700° C. In addition, when the CVDreaction temperature is 300° C. to 500° C., step coverage ratios, forexample, of at least about 0.8 can be achieved even for apertures withan aspect ratio of 10. The step coverage ratio can be defined as thevalue afforded by dividing the minimum film thickness at a step featureby the film thickness in a flat or planar region. The CVD reactiontemperature is usually the temperature of or near the substrate on whichthe silicon nitride is formed.

The hydrazine gas and precursor gas can be fed into the reaction chamberat a hydrazine/precursor flow rate ratio generally of no more than 100.While silicon nitride can be produced even when the hydrazine/precursorflow rate ratio exceeds 100, hydrazine/precursor flow rate ratios inexcess of 100 are generally uneconomical. Preferred values of thehydrazine/precursor flow rate ratio are from 1 to 80.

The inert dilution gas introduced on an optional basis into the reactionchamber can be an inert gas, for example, nitrogen or a rare gas such asargon.

Since neither the precursor nor the hydrazine used by this inventioncontains chlorine, their reaction does not generate the ammoniumchloride by-product that has heretofore been a problem. Moreover, whilethe silylhydrazine and/or hydrazine used by this invention includesspecies that contain carbon, a relatively low carbon concentration inthe silicon nitride product has been confirmed even for the use of suchcarbon-containing species.

The production of silicon nitride films by the use of silylhydrazine byitself and its thermal decomposition will now be considered. In thiscase, silylhydrazine gas is introduced into the reaction chamber, alongwith any inert dilution gas used on an optional basis, and a siliconnitride film is produced by thermal decomposition of the silylhydrazine.As in the CVD procedure considered above, the pressure in the reactionchamber can be maintained at from 0.1 torr to 1,000 torr, while thepressure in the reaction chamber is preferably maintained at from 0.1torr to 10 torr.

As with the CVD procedure considered above, decomposition of thesilylhydrazine gas can generally be carried out at temperatures from300° C. to 1,000° C. This silylhydrazine decomposition can producesilicon nitride at sufficiently high growth rates (film formation rate)even at low temperatures of 400° C. to 700° C. In addition, high stepcoverage ratios can be achieved when the decomposition temperature is300° C. to 500° C.

For both the CVD procedure and the thermal decomposition procedure, thesilylhydrazine gas can be prepared in advance and stored in a sealedcontainer until use or can be synthesized onsite and the gaseousreaction mixture containing the synthesized silylhydrazine gas can beintroduced into the reaction chamber. A silylamine gas and a hydrazinegas are introduced into a synthesis chamber in order to effect thisonsite synthesis of silylhydrazine gas. At this point, an inert dilutiongas, such as the inert dilution gas that may be introduced into thereaction chamber as discussed above, can also be introduced into thesynthesis chamber along with the aforementioned reaction gases. Withregard to the conditions during introduction of the silylamine gas andhydrazine gas into the synthesis chamber, the pressure in the synthesischamber should be maintained at 0.1 to 1,000 torr and the hydrazinegas/silylamine gas flow rate ratio should be 10 to 1,000. The two gasescan be reacted at temperatures ranging from room temperature to 500° C.Silylhydrazine is produced by this reaction. The resultingsilylhydrazine-containing gaseous reaction mixture within the synthesischamber can then be subjected to pressure adjustment by a pressureregulator and introduced into the above-described reaction chamber. Thesilylamine used here encompasses silylamine defined by formula (III)(H₃Si)_(m)N(H)_(3-m)  (III)wherein m is an integer from 1 to 3. The hydrazine introduced into thesynthesis chamber encompasses hydrazine defined by formula (IV)H(R^(x))N—N(R^(y))R^(z)  (IV)wherein R^(x), R^(y), and R^(z) are each independently selected from thehydrogen atom, methyl, ethyl, and phenyl.

Silylhydrazine (I), for example, can be produced by the reaction of thesilylamine (III) and hydrazine (IV).

FIG. 1 contains a block diagram of one example of a CVD-based apparatusfor producing silicon nitride films that is well-suited for executingthe inventive method for producing silicon nitride films. The apparatusillustrated in Example 1 uses a precursor gas source that containsalready prepared precursor gas.

The production apparatus 10 illustrated in FIG. 1 is provided with areaction chamber 11, a precursor gas source 12, a hydrazine gas source13, and a source 14 of inert dilution gas that may be introduced ascircumstances dictate.

A susceptor 111 is disposed within the reaction chamber 11, and asemiconductor substrate 112, such as a silicon substrate, is mounted onthe susceptor 111 (a single semiconductor substrate is mounted on thesusceptor 111 since the apparatus illustrated in FIG. 1 is asingle-wafer apparatus). A heater 113 is provided within the susceptor111 in order to heat the semiconductor substrate 112 to the prescribedCVD reaction temperature. From several semiconductor substrates to 250semiconductor substrates may be held in the reaction chamber in the caseof a batch apparatus. The heater used in a batch apparatus can have adifferent structure from the heater used in a single-wafer apparatus.

The precursor gas source 12 comprises a sealed container that holdsliquefied precursor. The precursor gas is introduced from its source 12through the precursor gas feed line L1 and into the reaction chamber 11.There are disposed in this line L1 a shut-off valve V1 for the precursorgas source 12 and, downstream from said shut-off valve V1, a flow ratecontroller such as, for example, a mass flow controller MFC1. Theprecursor gas is subjected to control to a prescribed flow rate by themass flow controller MFC1 and is introduced into the reaction chamber11.

The hydrazine gas source 13 comprises a sealed container that holdsliquefied hydrazine. The hydrazine gas is introduced from its source 13through the hydrazine gas feed line L2 and into the reaction chamber 11.There are disposed in this line L2 a shut-off valve V2 and, downstreamtherefrom, a flow rate controller such as, for example, a mass flowcontroller MFC2. The hydrazine gas is subjected to control to aprescribed flow rate by the mass flow controller MFC2 and is introducedinto the reaction chamber 11.

The inert dilution gas source 14 comprises a sealed container that holdsthe inert dilution gas. As necessary or desired, the inert dilution gasis introduced from its source 14 and into the reaction chamber 11through the inert dilution gas feed line L3. As shown in FIG. 1, theinert dilution gas feed line L3 can be joined with the precursor gasfeed line L1 and the inert dilution gas can thereby be introduced intothe reaction chamber 11 in combination with the precursor gas. There aredisposed in this line L3 a shut-off valve V3 and, downstream therefrom,a flow rate controller such as, for example, a mass flow controllerMFC3. The inert gas is subjected to control to a prescribed flow rate bythe mass flow controller MFC3 and is introduced into the reactionchamber 11.

The outlet from the reaction chamber 11 is connected to a waste gastreatment facility 15 by the line L4. This waste gas treatment facility15 removes, for example, the by-products and unreacted material, and thegas purified by the waste gas treatment facility 15 is discharged fromthe system. There are disposed in the line L4 a pressure sensor PG, apressure regulator such as a butterfly valve BV1, and a vacuum pump PM.The introduction of each gas into the reaction chamber 11 is carried outby the respective mass flow controllers, while the pressure within thereaction chamber 11 is monitored by the pressure sensor PG and isestablished at a prescribed pressure value by operation of the pump PMand control of the aperture of the butterfly valve BV1.

When the silicon nitride film is to be produced by thermal decompositionof the silylhydrazine gas, use of the hydrazine feed system (the source13, feed line L2, shut-off valve V2, and mass flow controller MFC2)becomes unnecessary and it need not be provided.

FIG. 2 contains a block diagram that illustrates an apparatus forproducing silicon nitride films that contains an onsite facility forproducing silylhydrazine. Those constituent elements in FIG. 2 that arethe same as in FIG. 1 are assigned the same reference symbol and theirdetailed explanation has been omitted.

The production apparatus 20 illustrated in FIG. 2, in addition to havingthe same type of reaction chamber 11 as the one illustrated in FIG. 1,contains a synthesis chamber 21 for the onsite synthesis ofsilylhydrazine. A heater 211 is disposed on the circumference of thissynthesis chamber 21 for the purpose of heating the interior of thesynthesis chamber 21 to the prescribed reaction temperature.

The production apparatus 20 illustrated in FIG. 2 lacks the precursorgas source 12 shown in FIG. 1 and contains a source 22 of a silylaminethat will react with the hydrazine to produce a silylhydrazine. Thesilylamine source 22 comprises a sealed container that holds thesilylamine in liquid form. Silylamine gas is introduced from this source22 through the feed line L21 and into the synthesis chamber 21. Thereare disposed in the line L21 a shut-off valve V21 and, downstreamtherefrom, a flow rate controller such as, for example, a mass flowcontroller MFC21. The silylamine gas is subjected to control to aprescribed flow rate by the mass flow controller MFC21 and is introducedinto the synthesis chamber 21.

The hydrazine gas source 13 is provided with a feed line L22 to thesynthesis chamber 21 in addition to the feed line L2 to the reactionchamber 11. There are disposed in this feed line L22 a shut-off valveV22 and, downstream therefrom, a flow rate controller such as, forexample, a mass flow controller MFC22. The hydrazine gas is subjected tocontrol to a prescribed flow rate by the mass flow controller MFC22 andis introduced into the synthesis chamber 21.

The inert dilution gas source 14 is provided with a feed line L23 to thesynthesis chamber 21 in addition to the feed line L3 to the reactionchamber 11. There are disposed in this feed line L23 a shut-off valveV23 and, downstream therefrom, a flow rate controller such as, forexample, a mass flow controller MFC23. As necessary or desired, theinert dilution gas is subjected to control to a prescribed flow rate bythe mass flow controller MFC23 and is introduced into the synthesischamber 21. The line L3 in the apparatus in FIG. 2 is directly connectedto the reaction chamber 11.

The outlet from the synthesis chamber 21 is connected by the line L24 tothe reaction chamber 11. A pressure regulator, for example, a butterflyvalve BV2, is provided in the line L24. The silylhydrazinegas-containing gaseous reaction mixture afforded by the synthesischamber 21 is introduced into the reaction chamber 11 after the pressurein the synthesis chamber 21 has been adjusted by the butterfly valve BV2as appropriate for introduction into the reaction chamber 11.

With regard to the handling of the precursor gas in the apparatusillustrated in FIG. 1 for producing silicon nitride films, the gas-phasematerial is withdrawn from the precursor gas source 12—which holds theprecursor gas in liquid form—and is introduced into the reaction chamber11 via the line L1 by opening the valve V1 and carrying out adjustmentusing the mass flow controller MFC1. However, the precursor gas can alsobe introduced into the reaction chamber 11 through the line L1 using abubbler or vaporizer. FIG. 3 illustrates a precursor gas feed systemthat uses a bubbler. This feed system, which is used in place of theprecursor gas source 12 and the valve V1 in the production apparatusillustrated in FIG. 1, is provided with a precursor gas source 32 thatholds precursor gas 31 in liquid form. The line L31 is inserted intothis precursor gas source 32 in order to bubble inert gas from a source33 of the same inert gas as described above into the liquid precursorgas 31 held in the precursor gas source 32. A shut-off valve V31 isdisposed in the line L31. The line L1 shown in the production apparatusof FIG. 1 is inserted into the precursor gas source 32 above the liquidsurface of the liquid precursor gas 31. A shut-off valve V32 is disposedin the line L1. Precursor becomes entrained in the inert gas when theinert gas is bubbled thereinto and is introduced into the reactionchamber 11 shown in FIG. 1 through the line L1 while being subjected toflow rate control by the mass flow controller MFC1.

FIG. 4 illustrates a precursor gas feed system that uses a vaporizer.This feed system, which is used in place of the precursor gas source 12and the mass flow controller MFC1 in the production apparatusillustrated in FIG. 1, is provided with a precursor gas source 42 thatholds precursor gas 41 in liquid form. A line L41 is provided to thisprecursor gas source 42 in order to introduce inert gas from a source 43of the same inert gas as described above, in such a manner that theliquid surface of the liquid precursor gas 31 is pressed by the inertgas. A shut-off valve V41 is disposed in the line L41. In addition, theline L1 in the production apparatus illustrated in FIG. 1 is insertedinto the precursor gas source 42 into the liquid precursor gas 41itself. There are provided in this line L1 a shut-off valve V42, aliquid mass flow controller LMFC41 downstream therefrom, and a vaporizer44 downstream from the liquid mass flow controller LMFC41. The liquidprecursor 41 pressed out by the introduction of inert gas from the inertgas source 43 flows through the line L1 and is subjected to flow ratecontrol by the liquid mass flow controller LMFC41 and is introduced intothe vaporizer 44. The liquid precursor is vaporized in this vaporizer 44and is then introduced into the reaction chamber 11 shown in FIG. 1.Inert gas can also be introduced into the vaporizer 44 through the lineL42 from the inert gas source 45 in order to promote vaporization of theliquid precursor in the vaporizer 44. There are disposed in this lineL42, for example, a mass flow controller MFC42 in order to control theflow rate of inert gas from the inert gas source 45 and, downstream fromsaid mass flow controller MFC42, a shut-off valve V43.

EXAMPLES

This invention will be described in additional detail by workingexamples as follows, but this invention is not limited to these workingexamples.

Example 1

This example used a production apparatus with the structure illustratedin Example 1. Silicon nitride films were produced on silicon substratesat different CVD reaction temperatures (T) while introducing TSA gas ata feed flow rate of 0.5 sccm or 4 sccm and 1,1-dimethylhydrazine (UDMH)gas at a feed flow rate of 40 sccm into a reaction chamber that held asilicon substrate. The pressure within the reaction chamber wasmaintained at 1 torr. The silicon nitride deposition (growth) rate wasmeasured during this process, and the obtained values are plottedlogarithmically in FIG. 5 against 1,000 times the reciprocal of thereaction temperature (T in K). Line a in FIG. 5 plots the results forthe feed of 0.5 sccm TSA gas (UDMH/TSA feed flow rate ratio=80), whileline b plots the results for a TSA gas feed of 4 sccm (UDMH/TSA feedflow rate ratio=10).

As may be understood from the results in FIG. 5, the silicon nitridefilm growth rate was larger at the smaller UDMH/TSA feed flow rate ratioand increased with increasing reaction temperature. However, the siliconnitride film growth rate was still high enough for practicalapplications even at a temperature as low as 480° C.

The composition of the obtained silicon nitride films as measured byAuger elemental analysis and ellipsometry was Si_(0.8-0.9)N. The carboncontent of the silicon nitride films prepared at a UDMH/TSA feed flowrate ratio of 80 was only 3 weight %. The etching rate of the individualsilicon nitride films by 0.25% aqueous hydrogen fluoride was measured at30-50 Å/min in all cases, which is substantially lower than the etchingrate of silicon nitride films afforded by PECVD.

The gaseous reaction mixture within the reaction chamber was alsoanalyzed by Fourier transform infrared spectroscopy (FTIR) in thisexample. It was confirmed at both UDMH/TSA feed flow rate ratios that(a) the intensity ratio (l(947)/l(2172)) for the two main peaks for TSA(the peak at about 947 cm⁻¹ assigned to the SiN bond and the peak atabout 2172 cm⁻¹ assigned to the SiH bond) underwent a change (see FIG.6) and (b) the peak assigned to the SiH bond shifted from 2172 cm⁻¹ to2163 cm⁻¹. These facts confirm that disilyidimethylhydrazine(SiH₃)₂N—N(CH₃)₂ was produced by the reaction of TSA and UDMH attemperatures ≧450° C. (see FIG. 6). The correlation and synthesis of thefacts associated with the production of silicon nitride films in thisexample enables the following to be said:

-   -   (i) silylhydrazine can be used as precursor;    -   (ii) silylhydrazine can be produced by the reaction of a        silylamine and a hydrazine; and    -   (iii) silicon nitride can be produced using the        silylhydrazine-containing gaseous reaction mixture produced by        the reaction of a silylamine and a hydrazine.

Example 2

Using a production apparatus with the structure shown in FIG. 1, siliconnitride films were formed at different reaction temperatures in areaction chamber holding a silicon substrate on which trenches(diameter: 0.6 μm) with an aspect ratio (depth/diameter) of 10 had beenformed. UDMH was introduced at a flow rate of 40 sccm; TSA gas wasintroduced at a flow rate of 4 sccm; and a pressure of 1 torr wasestablished in the reaction chamber. The step coverage ratios of thesilicon nitride films obtained at the different temperatures weremeasured by scanning electron microscopy (SEM), and the results arereported in FIG. 7.

The results reported in FIG. 7 not only show that the step coverageratio of the silicon nitride film product can be improved to about 0.8by establishing the reaction temperature at 500° C., but also enable theprediction that the step coverage ratio can be improved still further bysetting the reaction temperature at even lower values.

This invention has been described hereinabove through variousembodiments and working examples, but this invention is not limitedthereto. The various embodiments described above can be combined.

As has been described hereinabove, the inventive methods are notaccompanied by the production of ammonium chloride, avoid significantadmixture of carbonaceous contaminants in the film products, and alsoenable the production of silicon nitride films with better filmproperties even at relatively low temperatures.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 contains a block diagram that illustrates an example of anapparatus for producing silicon nitride films.

FIG. 2 contains a block diagram that illustrates another example of anApparatus for producing silicon nitride films.

FIG. 3 contains a block diagram of a precursor gas feed system that usesa bubbler.

FIG. 4 contains a block diagram of a precursor gas feed system that usesa vaporizer.

FIG. 5 contains a graph that shows the relationship between the CVDreaction temperature and the silicon nitride film growth rate.

FIG. 6 contains a graph that shows the relationship between theintensity ratio between the two main peaks for TSA and the reactiontemperature.

FIG. 7 contains a graph that shows the relationship between the CVDreaction temperature and the step coverage ratio for silicon nitridefilms.

1-17. (canceled)
 18. A method which may be used for producing a siliconnitride film by vapor-phase growth, wherein said method comprises: a)feeding a first hydrazine gas and at least one precursor gas into areaction chamber, wherein: 1) said precursor gas comprises at least onemember selected from the group consisting of: i) trisilylamine gas; andii) silylhydrazine gas; and 2) at least one substrate is located in saidreaction chamber; and b) forming a silicon nitride film on saidsubstrate by reacting said first hydrazine gas and said precursor gas.19. The method of claim 18, wherein: a) said silylhydrazine is definedby formula (I)H₃Si(R^(a))N—N(R^(b))R^(c)  (I); and b) R^(a), R^(b), and R^(c) eachcomprise at least one member selected from the group consisting of: 1)silyl; 2) hydrogen; 3) methyl; 4) ethyl; and 5) phenyl.
 20. The methodof claim 18, further comprising: a) creating said precursor gas in asynthesis chamber by reacting a silylamine gas with a second hydrazinegas to form a silylhydrazine gas; and b) feeding said precursor gas intosaid reaction chamber from said synthesis chamber.
 21. The method ofclaim 18, wherein: a) said first hydrazine gas is defined by formula(II)H(R¹)N—N(R²)R³  (II); and b) R¹, R², and R³ each comprise at least onemember selected from the group consisting of: 1) hydrogen; 2) methyl; 3)ethyl; and 4) phenyl.
 22. The method of claim 20, wherein: a) saidsilylamine is defined by formula (III)(H₃Si)_(m)N(H)_(3-m)  (III); and b) m is 1, 2, or
 3. 23. The method ofclaim 20, wherein: a) said second hydrazine is defined by formula (IV)H(R^(x))N—N(R^(y))R^(z)  (IV); and b) R^(x), R^(y), and R^(z) eachcomprise at least one member selected from the group consisting of: 1)hydrogen; 2) methyl; 3) ethyl; and 4) phenyl.
 24. The method of claim18, wherein the temperature of the reaction between said precursor gasand said first hydrazine gas is between about 300° C. and about 700° C.25. The method of claim 18, wherein the pressure in said reactionchamber is between about 0.1 torr and about 1000 torr.
 26. The method ofclaim 18, further comprising feeding an inert dilution gas into saidreaction chamber.
 27. A method which may be used for producing siliconnitride films by vapor-phase growth, said method comprising: a) feedinga silylhydrazine gas into a reaction chamber, wherein said chambercontains at least one substrate; and b) forming a silicon nitride filmon said substrate by a decomposition of said silylhydrazine gas.
 28. Themethod of claim 27, wherein: a) said silylhydrazine is defined byformula (I)H₃Si(R^(a))N—N(R^(b))R^(c)  (I); and b) R^(a), R^(b), and R^(c) eachcomprise at least one member selected from the group consisting of: 1)silyl; 2) hydrogen; 3) methyl; 4) ethyl; and 5) phenyl.
 29. The methodof claim 27, further comprising a) creating a silylhydrazine-containingreaction mixture in a synthesis chamber by reacting a silylamine gaswith a hydrazine gas; and b) feeding said silylhydrazine-containingreaction mixture into said reaction chamber.
 30. The method of claim 29,wherein: a) said hydrazine is defined by formula (IV)H(R^(x))N—N(R^(y))R^(z)  (IV); and b) R^(x), R^(y), and R^(z) eachcomprise at least one member selected from the group consisting of: 1)hydrogen; 2) methyl; 3) ethyl; and 4) phenyl.
 31. The method of claim29, wherein: a) said silylamine is defined by formula (III)(H₃Si)_(m)N(H)_(3-m)  (III) and b) m is 1, 2, or
 3. 32. The method ofclaim 27, wherein the decomposition of said silylhydrazine gas iscarried out at a temperature between about 300° C. and about 700° C. 33.The method of claim 27, wherein the pressure in said reaction chamber isbetween about 0.1 torr and about 1000 torr.
 34. The method of claim 27,further comprising feeding an inert dilution gas into said reactionchamber.
 35. A method which may be used for producing a silicon nitridefilm by vapor-phase growth, wherein said method comprises: a) feeding afirst hydrazine gas and at least one precursor gas into a reactionchamber, wherein: 1) said precursor gas comprises at least one memberselected from the group consisting of: i) trisilylamine gas; and ii)silylhydrazine gas; 2) at least one substrate is located in saidreaction chamber; and 3) the pressure in said reaction chamber isbetween about 0.1 torr and about 1000 torr; and b) feeding an inertdilution gas into said reaction chamber; and c) forming a siliconnitride film on said substrate by reacting said first hydrazine gas andsaid precursor gas, wherein the temperature of the reaction is betweenabout 300° C. and about 700° C.